Posted
by
Soulskill
on Friday September 07, 2012 @10:58AM
from the new-paint-job-and-millions-of-pounds-of-carrying-capacity dept.

An anonymous reader sends this excerpt from Transportation Nation:
"Retired space shuttles are being readied for museums, but there's one piece of equipment at the Kennedy Space Center that dates back to before the moon landing and it's not going anywhere. NASA's giant crawler transporter is the only machine with enough muscle to move Apollo rockets and space shuttles out to the launch pad, and after nearly 50 years on the job the agency's decided there's still no better way to transport heavy loads. It's about as wide as a six lane highway, higher than a two story building, with huge caterpillar treads at each of its four corners. ... Crawler two is being upgraded from its current lifting capacity of 12 million pounds — the combined weight of the shuttle and mobile launcher — to 18 million pounds, for NASA’s new heavy lift rocket."

It would have to be on a hell of an incline. The friction between the tracks and the suspension is enormous. I've ridden the thing a couple of times and they really have to gun the throttles to get everything rolling. After that, they throttle down just a bit to maintain a nice even pace.

Just as a point of argument, there ARE other ways to do this sort of thing. The Russians like to put things together on the ground and then lift the entire mess up. I'm sure there were spirited discussions on the pros and cons of doing this in the 60's but this way certainly has been quite flexible.

... but why don't they build the rocket on the take-off location and remove the building instead? It seems like a smaller effort, no?

This is exactly what's done in some circumstances. During the 80's, there were plans to launch shuttles from Vandernberg AFB in California. The West-Coast launch site was known as SLC-6 [wikipedia.org] and, if it had ever been used, would have worked in exactly this way. The downside is that the launch site is tied up for many months at a time. I believe SLC-6 was intended to handle around one launch per year.

When the plans for Kennedy were laid out in the early 60's, the method of getting to the moon was still being decided. Early on, the leading option was Earth orbit rendezvous, which would have required two Saturn 5 launches per mission, with the rockets launched within hours of each other. Having a central assembly building with a capacity for several Saturn 5s [1] and three separate launch sites (although only two were actually built) was seen as the best way of doing this. Everything there now is a legacy of this, early-60's planning.

However ESA in Kourou and the Russians in Baikonur do the same thing - separating assembly and launch sites. The hassle of having to move rockets about on the ground is more than made up for the fact that your launch rate isn't bottle-necked by the number of launch pads. And remember, the number of launch pads is always going to be limited as they have to be separated by many miles of empty land for safety reasons. Even on the Central Asian steppes, you'd only have space for so many.

[1] I believe it could potentially accommodate four at various stages of assembly but don't quote me, I'm likely misremembering the exact number.